Over half of all human cancers occur in squamous epithelia. In order to enhance drug discovery for the treatment of squamous cell carcinoma (SCC) and other cancers, it is essential to have an organotypic in vitro model which recapitulates tumor and normal epithelial interactions. The Allen-Hoffmann laboratory recently developed an organotypic model that permits the assessment of tumor growth in stratified human squamous epithelia. The model is a co-culture of genetically marked human SCC cells and unmarked spontaneously immortalized human keratinocytes called NIKS cells. Unlike current in vitro assays, this model accounts for the influence of the normal tissue microenvironment (NTM) on the growth and differentiation of SCC cells. Another advantage is the model's relevance for other epithelial cancers (e.g., cervix, trachea) and its capacity for combination with other treatments (e.g., surgery, radiation). Our strategy for this proposal is to validate and optimize the organotypic co-cultures in the presence of known and novel anticancer agents (e.g., chemotherapeutics, cytostatic drugs) and quantify their effect on malignant cell growth by monitoring the genetically marked SCC cells. Pending completion of this Phase I work, we plan to develop a high-throughput, microliter-volume screening format to identify novel anti-tumor agents using the NIKS-based, human NTM tumor assay. PROPOSED COMMERCIAL APPLICATION: It is essential for effective durg discovery that in vitro models be able to test potential anticancer agents in a physiologically relevant context. Stratatech is developing products and services using a co-cultured system of genetically tagged squamous cell carcinoma (SCC) cells in an organotypic culture comprised of our propietary NIKS cell line. This model system represents a major technological advance for screening drugs or agents of potential use in treating cancers of the stratified squamous epithelia (e.g., head and neck, oral mucosa, cervix, trachea).